> On Sat, Jan 17, 2009 at 11:22 PM, Tejun Heo <tj@kernel.org> wrote:> > > Hello, Brian.> >> > Brian Gerst wrote:> > > Accessing memory through %gs should not use rip-relative addressing.> > > Adding a P prefix for the argument tells gcc to not add (%rip) to> > > the memory references.> >> > Nice catch. I dind't know about the P prefix thing. It also is used> > in other places too. Hmmm... I can't find anything about the P> > argument prefix in the gcc info page (4.3). Any ideas where I can> > find some information about it? It's a bit weird that it's not a> > constraint prefix but an argument one.> > The only place I could confirm that it works is in the gcc source > itself, and even there it's not well documented.

does %P support go back as far as gcc 3.2 (the earliest GCC we still support)?